        (throw (IllegalArgumentException.
                 (format "Range start %d must be less than range end %d"
                         start end))))
-     (data/content-stream block start end))))
+     (io! (data/content-stream block start end)))))
 
 
 (defn read!

  block. If the block is already loaded, it is returned unchanged. The returned
  block will have the same metadata as the one given."
  [block]
  (if (lazy? block)
    (with-meta
      (data/read-block
        (:algorithm (:id block))
        (data/content-stream block nil nil))
      (meta block))
    block))


(defn validate!

   (scan store nil))
  ([store p]
   (->
     (list-seq store)
     (cond->>
       p (filter p))
     (->>
       (reduce sum/update (sum/init))))))


(defn sync!
